Serial Number: SB872 Body: F-G Shutter function Lens: 224mm D.R.P f / 12.5 (56,109) Optics: G c1892-1905. 3¼ × 4¼ plates, 4x5, 4¾ × 6½, or 3½x5½ '' box camera. Front sliding. Also known as special model B. After 1905 continued as universal special model B.